Looks to me that we're having two separate discussions going.

Let me reiterate what I find odd/strange/awkward. The vast majority (90%+) of players that are in my scan tab are way higher than my rank. If half of the said players would be way lower than my rank then what you say would make sense. The only conclusion I could draw, if I would be to use your information ("The battle tab shows you players that are plus or minus a x% of your rank") as valid, is that the said half of way lower players are stacking stealth madly therefore I see only higher ranked players. Do you understand what I'm trying to say ?

I realize this thread is somewhat old. I found it looking for different info, but I thought I might have an answer regarding the ranks of players showing up in your battle tab.

It could be a bracket thing. You may currently be in the lower portion of a level bracket.